Flash, as a kind of storage chip, combines advantages of ROM (Read Only Memory) and RAM (Random Access Memory), which is not only erasable and programmable but also can be read quickly and data will not be lost due to power down.
In the process of realizing the present invention, the inventors found that, based on characteristic that data of Flash can only be erased by taking a block or the whole piece as a unit, the prior art has following defections: the page size of some Flash chip is very big, however contents required to be updated each time are less in application. According to a general method at present, even there are only several bytes which are required to be updated each time, a free or empty physical page is required to be searched again and then content of an original page is updated in the RAM and the updated page is written on a new physical page. The method applied for data updating has low efficiency and shortens the life of the Flash.